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BACKGROUND: The yeast Pichia pastoris is a popular host organism for production of a range of biological products, several of which are intracellular. The disruption of yeast cells by homogenisation also releases large quantities of lipids, which can foul the downstream membranes and chromatography matrices used for purification. This work examines lipid removal from yeast cells following homogenisation by enzymatic degradation and its impact on the performance of the subsequent centrifugation and filtration. RESULTS: Lipase treatment of cell homogenate at 37°C for 2 hours, followed by clarification using a scale-down mimic of disc stack centrifugation, resulted in a 6.5-fold improvement in solids removal when compared to untreated feed material. The lipase treated and untreated materials that had undergone initial centrifugation were then tested for filtration performance by passing the material through a 0.45 μm polyethylene sulfone membrane under constant flux. A 50% increase in throughput was observed in comparison to the untreated material. CONCLUSION: This proof-of-concept data suggests enzymatic digestion of lipids, analogous to the widely performed DNA reduction using nucleases, could be a valuable process improvement strategy.

Microglia, myelo‐monocytic lineage cells, that enter in the developing brain at early embryonic stages and integrate in CNS, are involved in almost all neuroinflammatory conditions. We studied how microglia change their responses through the development and maturation of brain in normal physiological conditions using an ex situ model to delineate their age‐specific morpho‐functional responsiveness. Rapidly isolated microglia from different age‐matched rats were characterized with Iba1+/CD11b/c+/MHCclassII+, cultured, studied for cell‐cycle/proliferative potency, ROS generation and phagocytosis, viability and morphological analysis induced with GMCSF, MCSF, IL‐4, IL‐6, IL‐10, and IFN‐γ. The study showed marked differences in cellular properties, stability, and viability of microglia through ontogeny with specific patterns in their studied functions which were coherent with their in situ morpho‐functional attributes. Phagocytic behavior showed a notable shift from ROS independence to dependence toward maturation. Perinatal microglia were found persistent in ex situ environment and neonatal microglia qualified as the most potent and versatile responders for morpho‐functional variations under cytokine induced conditions. The study identified that microglia from infants were the most stable, adaptive, and better responders, which can perform as an ex situ model system to study microglial biology., Microglia, myelo‐monocytic lineage cells involved in almost all neuroinflammatory conditions were studied for their response through the development and maturation of brain in normal physiological conditions using an ex situ model for investigating their age‐specific morpho‐functional responsiveness. The study showed marked differences in stability and viability of microglia through ontogeny with specific patterns in their proliferation, ROS dependent phagocytosis and cytokine responsiveness through maturation stages. Microglia from infants were found stable, adaptive and better responsive than matured, which can perform as an ex situ model system to study microglial biology.

SUMMARY: Conservation agriculture (CA) practices such as zero tillage (ZT) and permanent raised beds (PB) accelerate deposition of soil organic matter and augment associated biological properties of soil through enhanced inputs of organic carbon. However, the potential benefit of CA under intensive cereal‐based systems for key soil health indicators (such as carbon pools and biological activities) is only partially known. Therefore, we analysed the effect of three medium‐term tillage practices and four intensive crop rotations on selected soil organic carbon pools and microbial properties. The tillage practices consist of ZT, PB and conventional tillage (CT) in main plots and four crop rotations (MWMb, maize–wheat–mungbean; MCS, maize–chickpea–Sesbania; MMuMb, maize–mustard–mungbean; MMS, maize–maize–Sesbania) in subplots. The experimental design was split‐plot with three replications. After 6 years, we observed a significant positive effect of CA practices on soil organic carbon (SOC) content, labile SOC fractions, soil microbial biomass carbon (MBC) and dehydrogenase activity (DHA). The total organic carbon (TOC) was greatly affected by medium‐term tillage and diversified cropping systems; it was larger for CA and MCS and MWMb systems. The interaction effect between tillage and cropping systems for SOC content was not significant at all soil depths. Significantly larger contributions (8.5–25.5%) of labile SOC pools to TOC at various soil depths were recorded in PB and ZT. There was a significant positive effect of CA practices and diversified crop rotations on MBC and DHA at all the soil depths and sampling times, but the interaction effect between tillage and cropping systems was not significant. Thus, our medium‐term (≥ 5‐years) study showed that the combination of CA (PB and ZT) practices and appropriate choice of rotations (MCS and MWMb) appears to be the most appropriate option for restoration and improvement of the soil health of light‐textured Inceptisols through the accumulation of soil organic matter (SOM) and improvement in soil biological properties. HIGHLIGHTS: Effect of conservation agriculture (CA) on soil labile carbon inputs and biological properties. Observed changes in SOC stock and C‐pools at different soil depths after 6 years. Significant effects of tillage and crop rotations observed for labile‐C pools. Adoption of ZT and PB enhanced SOC stock, C‐pools and microbial activity compared to CT.

Arsenic (As) induces pre-malignant and malignant dermatological lesions, non-dermatological health effects and cancers in humans. Senescence involves telomere length changes and acquisition of senescence-associated secretory phenotype (SASP), which promotes carcinogenesis. Though in vitro studies have shown that As induces senescence, population based studies are lacking. We investigated the arsenic-induced senescence, telomere length alteration and its contribution towards development of As-induced skin cancer. The study participants included 60 each of As-exposed individuals with skin lesion (WSL), without skin lesions (WOSL) and 60 unexposed controls. Exposure assessment of drinking water and urine was done. SA β-gal activity, ELISA, and quantification of senescence proteins, alternative lengthening of telomere (ALT) associated proteins and telomerase activity were performed. Relative telomere length (RTL) was determined by qPCR. A significantly higher number of senescent cells, over-expression of p53 and p21 were observed in the As-exposed individuals when compared to unexposed. SASP markers, MMP-1/MMP-3 were significantly higher in the WSL but not IL-6/IL-8. A significant increase of RTL was observed in the WSL group, which was telomerase-independent but exhibited an over-expression of ALT associated proteins TRF-1 and TRF-2 with higher increase in TRF-2. An increased risk for developing As-induced skin lesions was found for individuals having RTL greater than 0.827 (odds ratio, 13.75; 95% CI: 5.66–33.41; P

An impressive biodiversity (>10,000 species) of marine snails (suborder Toxoglossa or superfamily Conoidea) have complex venoms, each containing approximately 100 biologically active, disulfide-rich peptides. In the genus Conus, the most intensively investigated toxoglossan lineage (∼500 species), a small set of venom gene superfamilies undergo rapid sequence hyperdiversification within their mature toxin regions. Each major lineage of Toxoglossa has its own distinct set of venom gene superfamilies. Two recently identified venom gene superfamilies are expressed in the large Turridae clade, but not in Conus. Thus, as major venomous molluscan clades expand, a small set of lineage-specific venom gene superfamilies undergo accelerated evolution. The juxtaposition of extremely conserved signal sequences with hypervariable mature peptide regions is unprecedented and raises the possibility that in these gene superfamilies, the signal sequences are conserved as a result of an essential role they play in enabling rapid sequence evolution of the region of the gene that encodes the active toxin.

Background and purpose: Although resveratrol is currently being evaluated in pre-clinical studies as a potential cancer chemopreventive agent and cardiovascular stress-releasing compound, treatment with resveratrol severely delays healing of pre-existing gastric ulcers. Resveratrol treatment can also induce endothelial NOS (eNOS) expression. Here, we have attempted to modulate NO production via eNOS in order to alleviate the pro-ulcer effects of resveratrol. Experimental approach: Gastric ulcers were induced in mice with a single dose of indomethacin. The effects of pretreatment with l-arginine on the pro-ulcer effects of resveratrol in these mice were then assessed. We measured ulcer damage scores (DS), myeloperoxidase (MPO) activity, generation of prostaglandin E2 (PGE2) and NO, along with a gene expression study. Key results: Resveratrol significantly aggravated damage from indomethacin-induced gastric ulcers, and delayed healing, as shown by increased DS and MPO activity. The mRNA for cyclooxygenase (COX)-1, but not that for COX-2, was inhibited by resveratrol treatment, with reduced synthesis of PGE2 by gastric tissue. However, resveratrol treatment induced eNOS gene expression and shifted the eNOS/iNOS balance. l-Arginine given before resveratrol in mice with indomethacin-induced ulcers significantly increased tissue NO synthesis and improved ulcer healing. Conclusions and implications: Exogenous l-arginine increased NO formation via raised levels of eNOS induced by resveratrol and protected against the pro-ulcer effects of resveratrol. Therefore, l-arginine might be useful for alleviation of the pro-ulcer side effects of resveratrol in patients.

Understanding the processes of soil organic carbon (SOC) accumulation or depletion under different management strategies is vital for maintaining soil health and curbing global warming. Using a 36-year-old fertility experiment under subtropical climate, we investigated the impact of long-term intensive rice-rice cropping system with different managements on the SOC stock. The mechanistic pathway of stabilization of the SOC into different pools, with a tentative C budgeting was also established. Biochemical composition of the organic residues involved, SOC pools of different oxidizability and methane (CH 4 ) emission were estimated for the experiment conducted using organic and inorganic sources of nutrients. Cultivation over the years caused a net decrease in SOC stocks but with balanced fertilization it increased. With increasing depth, the stock decreased on average, to the extent of 50%, 26% and 24% of the total at 0-0.2, 0.2-0.4 and 0.4-0.6 m, respectively. About 4.0% of the crop residues C incorporated into the soil were stabilized into SOC. This was further enhanced (1.6 times) by the application of compost. Carbon loss through CH 4 emission was very low (2.6% of the total). 'Summer fallow' had a positive significant influence on C loss from the system. As much as 29% of the compost C added to the soil was stabilized into SOC mostly in the less-labile or nonlabile recalcitrant pools preferentially in the surface layer of the soil. Large polyphenol and lignin contents of crop residues including compost, and the long period of soil submergence under rice cultivation might have conferred recalcitrant character to the SOC leading to its stabilization in nonlabile pools. This would result into an enrichment of the SOC stock and restriction to the gaseous C loading into the atmosphere.

Soil organic C (SOC) pools under long-term management practices provide information on C sequestration pathways, soil quality maintenance, and crop productivity. Farmyard manure (FYM), paddy straw (PS), and green manure (GM) along with inorganic fertilizers were used in a 19-yr-old rice (Oryza sativa L.)-wheat (Triticum aestivum L.) cropping system in subtropical India to evaluate their impact on SOC stock, its different pools-total organic C (C tot ); oxidizable organic C (C oc ) and its four fractions of very labile (C frac1 ), labile (C frac2 ), less labile (C frac3 ), and nonlabile C (C frac4 ); microbial biomass C (C mic ); and mineralizable C (C min ). Cropping with only N-P-K fertilization just maintained SOC content, while N-P-K plus organics increased SOC by 24.3% over the control, their relative efficacy being FYM > PS > GM. A minimum of 3.56 Mg C ha -1 yr -1 was required to be added as organic amendments to compensate for SOC loss from cropping. The passive (C frac3 + C frac4 ) pool and C min constituted about 39 and 11.5%, respectively, of C tot . Organics contributed toward the passive pool in the order FYM > PS > GM. Most of the pools were significantly (P = 0.005) correlated with each other. Yield and sustainable yield index were strongly related with C frac1 , C oc , C mic , and C min . Results suggest C frac1 as a useful indicator for assessing soil health, and balanced fertilization with FYM as suitable management for sustaining crop productivity of the rice-wheat system.

An understanding of the dynamics of carbon (C) stock in soils, as impacted by management strategies, is necessary to identify the pathways of C sequestration in soils and for maintaining soil organic C (SOC) at a level critical for upkeeping soil health and also for restraining global warming. This is more important in tropical and subtropical region where soils are inherently low in organic C content and the production system is fragile. We evaluated the long-term role of crop residue C inputs to soil in SOC sequestration and also the critical value of C inputs for maintenance of SOC across five different rice-based cropping systems and four soil management practices including a fallow (no cultivation since initiation of the experiments) using five long-term (7–36 years) fertility experiments in subtropical India. Cropping per se always caused a net depletion of SOC. Such depletion was inversely proportional to the amount of crop residue C incorporated into the soils (r=−0.92, P=0.001). Balanced fertilization with NPK, however, caused an enrichment (9.3–51.8% over the control) of SOC, its extent being influenced by the cropping systems. Long-term application of organic amendments (5–10 Mg ha−1 yr−1) through farmyard manure (FYM) or compost could increase SOC hardly by 10.7% constituting only 18% of the applied C, the rest getting lost through oxidation. The total quantity of soil C sequestered varied from −11.5 to 14.5 Mg C ha−1 and was linearly related (r2=0.40, P=0.005) with cumulative crop residue C inputs to the soils. On an average, the rate of its conversion to SOC came out to be 6.4%. This was more in presence of added organics (6.9%) than in its absence (4.2%). For sustenance of SOC level (zero change due to cropping) we found that a minimum quantity of 2.9 Mg C is required to be added per hectare per annum as inputs. The cropping systems and the management practices that could provide C input higher than the above critical level are likely to sustain the SOC level and maintain good soil health in the subtropical regions of the Indian subcontinent.

Variational studies on spiked oscillators with the potential form x 2 /x in (0, ) reveal certain limitations of the conventional choices for wave functions in the 2 regime. A careful analysis shows the necessity of properly incorporating the Dirichlet boundary condition at x 0. Subsequent pilot calculations on this notion perform nicely, justifying the worth of the endeavor. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem 106: 390 - 400, 2006

We show that logarithmic perturbation theory nicely yields the wavefunction correction terms in closed forms for the spiked perturbation λ/x2 on the first excited state of the harmonic oscillator, where the conventional Rayleigh-Schrodinger scheme is known to encounter serious problems. The study also provides a direct route to obtain several sum rules, some of which appear to be new. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005

We exploit the interrelation among the parameters embedded in the maximum entropy ansatz to develop a scheme for obtaining accurate estimates of the ground-state energy and wave function of systems for which the potential is represented by a rational function. Our scheme reduces an N-parameter optimization problem to a two-parameter one, leading to considerable simplification of the prevalent strategy. An indirect route for the study of excited states is also sketched. Test calculations on hydrogenic systems subject to strong or superstrong radial magnetic fields with and without electric field reveal the advantages of our approach. Additional studies on 1-D anharmonic oscillators affirm its workability and generality. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002

We present logarithmic perturbation theory in its simplest form that rests only on matching of certain polynomial coefficients at each order. It thus avoids any integration step in the course of calculations of energy correction terms at various orders. The scheme applies to excited states as well. Corrections to nodal point shifts are also obtained without quadratures. A few existing variants of the theory are compared and certain anomalies rectified. Merits and demerits of the approach are pointed out. We also outline a direct route to obtain perturbation series for properties through this route. This renders tedious computations of wave function correction terms at each order, obeying the corresponding normalization requirement, unnecessary, thus achieving further simplification. Pilot calculations on several model systems reveal the worth of the endeavor. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem 90: 27-36, 2002

— The Devri-Khera meteorite fell on 1994 October 30 in the Jhalwar district of Rajasthan, northwestern India. The texture, mineralogy and mineral and bulk compositions show that Devri-Khera is an L6 chondrite of shock facies S4.

Predatory cone snails (genus Conus) comprise what is arguably the largest living genus of marine animals (500 species). All Conus use complex venoms to capture prey and for other biological purposes. Most biologically active components of these venoms are small disulfide-rich peptides, generally 7-35 amino acids in length. There are probably of the order of 100 different peptides expressed in the venom of each of the 500 Conus species [1,2]. Peptide sequences diverge rapidly between Conus species, resulting in a distinct peptide complement for each species. Thus, the genus as a whole has probably generated approximately 50 000 different peptides, which can be organized into families and superfamilies with shared sequence elements [3]. In this minireview, we provide a brief overview of the neuropharmacological, molecular and cell-biological aspects of the Conus peptides. However, the major focus of the review will be the remarkable array of post-translational modifications found in these peptides.

All 500 species of cone snails (Conus) are venomous predators. From a biochemical/genetic perspective, differences among Conus species may be based on the 50-200 different peptides in the venom of each species. Venom is used for prey capture as well as for interactions with predators and competitors. The venom of every species has its own distinct complement of peptides. Some of the interspecific divergence observed in venom peptides can be explained by differential expression of venom peptide superfamilies in different species and of peptide superfamily branching in various Conus lineages into pharmacologic groups with different targeting specificity. However, the striking interspecific divergence of peptide sequences is the dominant factor in the differences observed between venoms. The small venom peptides (typically 10-35 amino acids in length) are processed from larger prepropeptide precursors (ca. 100 amino acids). If interspecific comparisons are made between homologous prepropeptides, the three different regions of a Conus peptide precursor (signal sequence, pro-region, mature peptide) are found to have diverged at remarkably different rates. Analysis of synonymous and nonsynonymous substitution rates for the different segments of a prepropeptide suggests that mutation frequency varies by over an order of magnitude across the segments, with the mature toxin region undergoing the highest rate. The three sections of the prepropeptide which exhibit apparently different mutation rates are separated by introns. This striking segment-specific rate of divergence of Conus prepropeptides suggests a role for introns in evolution: exons separated by introns have the potential to evolve very different mutation rates. Plausible mechanisms that could underlie differing mutational frequency in the different exons of a gene are discussed.

A study dealing with ecological sustainability of plantation based land use initiated in 1991 in a 19 yr old coconut plantation consists of growing certain leguminous crops like Atylosia, Pueraria, Centrosema and Calopogonium as soil cover in separate plots with lemon grass as live bounds. These cover crops are grown during the rainy season and incorporated into the soil towards the end of the monsoon every year. The effect of such cover crops on soil microbial counts (total counts, fungi, actinomycetes and bacteria), biomass C, organic C, total N and on the activity of enzymes like urease, amidase, L-glutaminase, aryl sulphatase and dehydrogenase was determined in soils (Ap horizon) collected from these plots after 5 years. Soils with cover crops registered significantly higher microbial biomass, biomass C, organic C and total N compared to control. Consequently, all the enzymes were activated to different degrees in soils with cover crops. Significant and positive relationships of enzyme activities with organic C, mineral N and total N suggested that growing cover crops, increased C turnover and N availability and therefore, provided a conducive environment for microbial proliferation, enzyme synthesis and accumulation in the soil matrix. Einflus von Leguminosen als Deckfrucht auf mikrobielle und ausgewahlte Enzymaktivitaten in Boden einer Plantage Zur Untersuchung der okologischen Nachhaltigkeit der Bodennutzung im Plantagenanbau wurde 1991 in einer 19 Jahre alten Kokosplantage ein Versuch mit Leguminosen als Deckfrucht auf getrennten Parzellen und mit Lemongrass als Trennstreifen angelegt. Die Deckfruchte wuchsen wahrend der Regenzeit und wurden gegen Ende des Monsuns alljahrlich eingearbeitet. Nach 5 Jahren wurde in Ap-Proben die Wirkung der verschiedenen Deckfruchte auf Mikroorganismen (Gesamtzahlen, Pilze, Actinomyceten und Bakterien), Biomasse-C, org. C und Gesamt-N und auf die Enzymaktivitaten wie Urease, Amidase, L-Glutaminase, Arylsulfatase und Dehydrogenase untersucht. Boden mit Deckfrucht wiesen signifikant hohere Werte bei mikrobieller Biomasse, Biomasse-C, org. C sowie mineralischem und Gesamt-N auf als die Kontrolle. Als Folge waren unter Deckfrucht alle Enzymaktivitaten — in unterschiedlichem Grade erhoht. Signifikante positive Korrelationen von Enzymaktivitaten mit organischem C, mineralischem und Gesamt-N sind Anzeichen dafur, das unter den wachsenden Deckfruchten Kohlenstoffumsatz und N-Verfugbarkeit gunstig beeinflust waren und damit mikrobielles Wachstum und Enzymsynthese und -anreicherung gefordert wurden.

Peptides from the venom ducts of cone snails (genus Conus) contain gamma-carboxyglutamate residues. The gamma-glutamyl carboxylase responsible for this post-translational modification is localized in the microsomal fraction, strictly dependent on vitamin K, activated by ammonium sulfate, and is associated with endogenous substrate. The K(m) of the enzyme for vitamin K is comparable to that for the bovine carboxylase. However, a propeptide containing substrate related to the blood coagulation protein factor IX, a highly efficient substrate for the bovine enzyme, was poorly carboxylated by the Conus enzyme, suggesting differences in gamma-carboxylase recognition signal sequences and/or structural requirements at the carboxylation site.

Four varieties of limestone distinguished on the basis of pore-size distributions were exposed in dynamic 10-, 20- and 50-ppm SO{sub 2} atmospheres for up to 500 h at 25 C and 100% rh. The resulting conversion of the limestone was measured as a function of the reaction product formed and the change in porosity. These conversions could be predicted correctly using either the shrinking unreacted core model or the distributed pore model. An artificial neural network (ANN) was also trained for the purpose. All three approaches predicted conversions that fitted well with the observed data; however, those predicted by ANN were the most accurate. Further, the weights determined for ANN on the basis of three limestone varieties also accurately predicted the conversions of the fourth variety for which no information was supplied in the training phase, showing that ANN can also be used successfully to estimate gas-solid noncatalytic reactions.

The Great Sphinx of Giza is considered by Egyptologists to have been excavated by the Pharaoh Kephren nearly 4500 years ago. Schoch and West (1991) have suggested that the Sphinx is much older, based primarily upon the rounded profile of the strata of the Sphinx thorax and the deep channels present in the walls surrounding the Sphinx ditch. These features, according to them, are due to “precipitation-induced weathering” formed when the Sahara still experienced a humid climate at least 7000 years ago. In this article we show how weathering in an arid environment can produce the rounded profile given the gradual change in lithology of the alternating hard and soft limestone strata. We show further that the channels are actually the pre-Pliocene karst features formed by underground water and exposed due to the excavation of the Sphinx ditch. We propose therefore that, for now, the Sphinx may still be regarded as of pharaonic origin. © 1995 John Wiley & Sons, Inc.

The preparation and characterization of two discrete, mixed-metal, hexanuclear transition-metal borides, trans-[Fe 4 Rh 2 (CO) 16 B] - and mer-H 2 Fe 3 Rh 3 (CO) 15 B, are described

An efficient procedure for the synthesis of chiral allylic amines from 5-iodomethyl-2-oxazolidinones using indium metal in refluxing methanol is described.

Anhydrous ytterbium(III) triflate-catalyzed ring opening of aromatic 1,2-epoxides with allyltributyltin in THF results in the formation of bishomoallyl alcohols in excellent yields and with complete regioselectivity. The results are compared with those obtained with allylmagnesium bromide as allylating agent.

The energy of formation of different interstitial configurations in f.c.c. metals using pseudopotential approach is formulated. A model calculation is done with a Ashcroft-Hubbard model potential for copper, silver, and gold. The calculation is indicates that the (100) split configuration is most stable and has a minimum energy which is consistent with other theoretical predictions and experimental observations.

SIR, – Foot-and-mouth disease (FMD) outbreaks due to serotype O virus were recorded in the Andaman and Nicobar Islands, India, during January to March 2005. This is significant because FMD has previously been recorded in these islands only during 1985 and 1989. Live animals brought from the state

Magnetic monopoles were first considered in detail by DIRAC in a 1931 paper, where he proved a charge-quantization theorem. The experimental searches which followed proved fruitless. Recently there has been a rapid increase in theoretical and experimental work in this field. A highly controversial detection claim was made by PRICE, SHIRK, OSBORNE and PINSKY in 1975. Report has also come of a possible monopole detection at Stanford university in February, 1982.

Because a blend of limited miscibility level produces high damping characteristics in a composite, copolyurethanes of different molecular structure were synthesized to achieve a desired level of miscibility in PVC. A study of the viscoelastic properties of blends of a 50-to-50 weight ratio of polyurethanes and PVC showed a steady decrease in miscibility on replacement of polyurethanes synthesized from polycaprolactone diols with a molecular weight of 2000, with polyurethanes synthesized by poly(ethylene oxide) diols, up to 80 mol percent, whereupon the polyurethanes became immiscible. The temperature range of damping for a particular polyurethane could be controlled by adjusting the ratio of PVC to the polyurethane. More polyurethane in the blend shifts the damping range toward lower temperature, and vice versa.

Energy conversion through photoelectrochemical cells with electrodeposited thin films of n-CdTe annealed separately in nitrogen and vacuum is discussed. The opto-electronic properties of the films (annealed in the two ambients) are calculated and the results analysed in terms of the depletion layer theory. The conversion efficiency is found to improve by annealing the semiconductor in vacuum. The improvement in cell performance is attributed to the removal of Te from the CdTe surface under the influence of vacuum. Es wird die Energieumwandlung durch photoelektrochemische Zellen mit elektrodisch abgeschiedenen dunnen n-CdTe-Schichten, die separat in Stickstoff und Vakuum getempert werden, diskutiert. Die opto-elektronischen Eigenschaften der Schichten (die in den beiden Umgebungen ausgeheilt werden) werden berechnet und die Ergebnisse mit der Theorie der Verarmungsschicht analysiert. Es wird gefunden, das sich die Konversionseffizienz durch Tempern des Halbleiters im Vakuum erhoht. Die Verbesserung der Zellenleistung wird der Beseitigung von Te aus der CdTe-Oberflache unter Vakuumeinflus zugeschrieben.

We present here the analysis of an accelerator produced 10 + 13p shower event observed in nuclear emulsion. The DULLER-~ALKF.R method is applied to obtain the distribution of secondary shower particles, and the particles having the closest log,, tan Ot values are taken to form a cluster. This cluster formation is also confirmed by the target diagram method. If this cluster is conceived to be a high spin resonance and the secondary pions to be the decay products of this resonance, then the azimuthal integral distribution curve fits fairly well with our experimental data.

Photoemulsion plates exposed to 70 GeV proton beam from Serpukhov Accelerator, USSR, have been analysed and part of the data has been utilized to obtain the distribution of the secondary particles in order to ascertain their production mechanism in the fireball model. This intermediate state for the production of secondaries has been identified from log tan θ plot and from the target diagram method. The parameters of the fireball were calculated by the method used by AGNESE et al. It is seen that the fireball model is favourable in 16% of the events studied. The average mass of the fireball is found to be (2.80 ± 0.1) GeV and its momentum to equal 169.62 MeV/c. The polar rotated angular distribution gives a good fit to the experimental data. Mechanismus der Mesonen-Entstehung bei 70 GeV Mit dem 70 GeV-Protonenstrahl des Serpukhov-Beschleunigers (UdSSR) bestrahlte Foto-Emulsionsplatten wurden analysiert und aus einem Teil der erhaltenen Daten die Verteilung der Sekundarteilchen ermittelt sowie deren Erzeugungsmechanismus im Rahmen des Feuerballmodells untersucht. Dieser Zwischenzustand bei der Erzeugung der Sekundarteilchen war aus der log tan θ-Kurve und mit Hilfe der Target-Diagramm-Methode zu erkennen. Die Parameter des Feuerballs wurden nach der Methode von AGNESE et al. berechnet. Es wird gezeigt, das das Feuerballmodell 16% der Ereignisse beschreibt. Die mittlere Masse des Feuerballs betragt (2,80 ± 0,1) GeV und sein Impuls 169,6 MeV/c. Die berechnete integrale Winkelverteilung stimmt mit den experimentellen Ergebnissen gut uberein.

The transverse momentum distribution of 900 secondary pions produced in interactions of 24 CeV protons with emulsion nuclei is seen to agree fairly well with the HAGEDORN distribution for ‘u’ = 312 and ‘Y adjusted to 133 MeV. A satisfactory fit of FEYNMANS scaling idea is also observed at this incident energy.

The plasticization of poly(vinyl chloride) (PVC) by polyurethanes made from polycaprolactone (PCL) diol and p.p′-diphenylmethane diisocyanate (MDI) was investigated. By varying the PCL chain length and substituting with polyether chains such as poly(tetramethylene ether) (PTME) or poly(ethylene oxide) (PEO), also of various chain lengths, the efficiency of plasticization was changed. High urethane content, such as obtained with PCL-530/MDI, decreased the miscibility of the polyurethane and PVC. Plasticizing efficiency of the polyurethanes, as indicated by transparency, flexibility, and engineering properties of the blend, increased on increasing the initial PCL chain length. However, polyurethanes containing very high-molecular-weight PCL (e.g., PCL-3000) slowly crystallized from a 50:50 blend with PVC. PVC/polyurethane ratio also had a significant effect on crystallization, as indicated by the rapid crystallization of PCL-2000/MDI polyurethane when it exceeded 50 wt % in the blend. The transparency and flexiblity of 50:50 blends were lowered by systematically replacing PVC-miscible PCL-2000 segments in the polyurethane with PTME-2000, PEO-200, and PEO-1500 segments. The polyurethanes became highly immiscible in PVC beyond the limiting mole fraction replacements of 0.6 for PTME-2000, 0.8 for PEO-200, and 0.4 for PEO-1500. Such chemical modification gave controlled and temperature-dependent miscibility in PVC and consequently blends with broadened glass transitions and high damping properties over a wide temperature range. Decreased miscibility in the blend gradually decreased elongation at break and tensile strength, but increased the modulus. A general correlation of the viscoelastic and tensile properties of the 50:50 blends with the weight fraction, rather than mole fraction, of the PCL content in the polyurethane composition was found; replacement of PCL beyond a limiting weight fraction by polyethers and MDI produced PVC-immiscible polyurethane. These limiting weight fractions are 0.6, 0.5, and 0.4 with PTME-2000, PEO-200, and PEO-1500, respectively, which denotes the order of decreasing miscibility of these polyurethanes in PVC. Viscoelastic and engineering properties of the blend with a particular polyurethane could also be controlled by varying the PVC/polyurethane ratio. Many of these semimiscible blends showed evidence by lower critical solution temperature (LCST) behavior at about −30°C, but complete cloud and point curves were not constructed.

Photovoltaic performance of liquid junction solar cells using electrodeposited thin film n-CdSe is found to be significantly affected by the nature of the annealing ambient. Effects of nitrogen and vacuum (10−4Torr) as the ambients upon the solar cell parameters are reported. Annealing in vacuum results in an increase of minority carrier diffusion lenght and short circuit current with consequent improvement in conversion efficiency. The improvement in cell performance is attributed to the removal of selenium acceptors under the influence of vacuum. Fonctionnement photovoltaique des cellules solaires avec la jonction liquide, utilisant less couches minces de n-CdSe preparees par electrolyse, est observe d'ětre significativement affecte par des natures d'ambiance de traitement. Les effects de nitrogene et de la vide qui constituent les environs. sur la parametres de cullule solaire sont rapportes. Traitement dans la vide resulte a une augmentation de la longeur de diffusion des porteurs minoritaires et du courant de court-circuit, avec l'amelioration de rendement de Conversion. L'amelioration du fonctionnement des cellules est attribuee a demenagement des accepteurs seleniums sous l'influence de la vide.

In ritro plasma adsorption over either protein A-positive Staphylococcus aureus Cowan I (SAC) or protein A-negative S. aureus Wood 46 (SAW) led to leaching of bacterial biomolecules in the postadsorbed plasma. Presence of bacterial moieties was demonstrated in the postadsorbed plasma by more than one method: (1) using radiolabeled bacteria for adsorption with plasma and detecting radioactivity in the postadsorbed plasma, (2) gel filtration of pre- and post-adsorbed plasmas over Sephadex C-200 column and detecting additional peak(s) in the postadsorbed plasma, and (3) immunoelectrophoretic analysis of pre- and postadsorbed plasmas and their column fractions against rabbit anti-SAC antisera and demonstrating new precipitin bands in postadsorbed plasmas. Using an extracorporeal plasma adsorption procedure in mongrel dogs, with radiolabeled SAC as the adsorbent, we have demonstrated the presence of radioactivity in both the adsorbed and filtered (0.2 wm) blood entering into the body, and the adsorbed blood that passed out of the body to reenter into the extracorporeal circuit. These data suggest that components of S. aureus origin enter into the host circulation during both in virro and ex vivo plasma adsorption, although the exact nature of those extracted staphylococcal components remains unknown. This observation is of much significance since it can possibly help elucidate the mechanism of tumor regression observed following perfusion of plasma over SAC or SAW, followed by its reinfusion to the host. Cancer 56:266-272, 1985

The sulfur vulcanization of NR by a MBT-TMTD mixed accelerator system both in the presence and absence of ZnO and stearic acid with or without DCP has been studied. The rate of decomposition of DCP in the presence of both MBT and TMTD is quite similar to that in the MBT system alone. The reduction in crosslinking due to DCP is dependent mainly on MBT. The decomposition product of TMTD may contribute to it only at the later stage of vulcanization. Though TMTD has no influence on the decomposition rate, it reacts with MBT at least in the initial stage of vulcanization and suppresses the retardation caused by MBT on DCP vulcanization in accordance with the free sulfur decrease, the nature of crosslinking formation both in the presence and absence of DCP, and the methyl iodide treatment of the vulcanizates. The vulcanization process of the MBT-TMTD-S-NR system has been interpreted in terms of both free radical and polar mechanisms. The domination of either of these depends on the dominant amount of either MBT or TMTD in the acclerator ratio. According to the initial high rate of crosslink formation, free sulfur decrease and also the initial additiveness of crosslinking in stocks containing DCP, the vulcanization process of MBT-TMTD-ZnO-St. acid-S-NR system has been explained in terms of an ionic mechanism. The pronounced synergistic nature of such systems has been interpreted by the enhanced activation of MBT-S-ZnO-St. acid complex due to the dithiodicarbamate ion formed in the initial stages of vulcanization, and also by the activation of TMTD accelerated vulcanization due to the mercaptobenzothiazylion.

Sulfuration of natural rubber (NR) by the binary accelerator 2-mercaptobenzothiazole (MBT) and diphenylguanidine (DPG) both in presence and in absence of ZnO and stearic acid with or without dicumylperoxide (DCP) was studied in detail. It was observed that the rate of decomposition of DCP in presence of both MBT and DPG is quite similar to that with MBT alone. The reduction of crosslinking depends also on MBT only. Through DPG has no influence on the decomposition rate, it reacts with MBT during the vulcanization process and suppresses the retardation caused by MBT on the DCP vulcanization. In accordance with the initial additiveness of crosslinking in systems containing DCP, the free sulfur decrease, and the rapidity of crosslink formation the vulcanization process of MBT-DPG-S-NR systems was interpreted in terms of a polar mechanism induced by the complex MSH2NR′R″. In mixtures containing DCP together with sulfur, MBT, DPG, ZnO, and stearic acid, the initial stage of crosslinking is additive as indicated by a mixed reaction as well as by a methyl iodide treatment of the vulcanizates. Comparison with single accelerators shows a pronounced synergistic effect. This is because of the enhanced activity of the MBT-ZnO-stearic acid complex due to DPG which also induces polar sulfuration of NR by forming the active complex MSH2NR′R″. In presence of ZnO and stearic acid, DCP cannot increase the net crosslink density but suppresses the reversion so much pronounced in its absence. Die Schwefelvukanisation von Naturkautschuk mit der binaren beshleunigermischung aus 2-Mercaptobenzthiazol (MBT) und Diphenyiguanidin (DPG) sowohl mit als auch ohne ZnO und Stearinsaure wurde mit und ohne Dicumylperoxid (DCP) eingehend untersucht. Dabei zeigte sich, das die Zersetzungsgeschwindigkeit von DCP in Gegenwart von MBT und DPG derjenigen bei alleinigem Vorhandensein von MBT ganz ahnlich ist. Die verringerte Vernetzung ist nur von MBT abhangig. Obwohl DPG keinen Einflus auf die Zersetzungsgeschwindigkeit ausubt, reagiert es mit MBT wahrend der Vulkanisation und unterdruckt die von MBT verursachte Verzogerung. In Ubereinstimmung mit der Anfangsadditivitat der Vernetzung in DCP enthaltenden Systemen, der freien Schwefelabnahme und der Geschwindigkeit der Vernetzung wurde der Vulkanisierungsprozes des MBT-DPG-S-NR-Systems durch einen durch MSH2NR′R″ induzierten polaren Mechanismus erklart. In Gemischen, die DCP zusammen mit Schwefel, MBT, DPG, ZnO und Stearinsaure enthalten, ist das Anfangsstadium der Vernetzung additiv, was durch gemischte Reaktionen und durch Methyljodid-Behandlung der Vulkanisate bestatigt wird. Ein Vergleich rnit einzelnen Beschleunigern zeigt deutlich einen synergistischen Effekt. Dies wird von der gesteigerten Reaktivitat des MBT-ZnO-Stearinsaure-Komplexes gegenuber DPG verursacht, das durch die Bildung des aktiven Komplexes MSH2NR′R″ auch eine polare Vulkanisation von Naturkautschuk induziert. Bei Anwesenheit von ZnO und Stearinsaure kann DCP die Vernetzungsdichte nicht vergrosern, es unterdruckt aber die bei seiner Abwesenheit deutliche Vernetzungsabnahme.

The effectiveness of the electrical resistivity method has been studied using various configurations with different spacings over the Southern Boundary Fault in the northwestern part, and across a dolerite dyke named “Salma dyke” in the central part, of the Raniganj Coalfield, India. It has been observed that the delineation of the fault and the dyke was made possible under differential tropical weathering conditions. Geoelectric sections across the fault and the dyke have been prepared on the basis of Schlumberger sounding results. In profiling, Wenner, two-electrode, half-Schlumberger and part of Al-Chalabi's configurations were applied over the Southern Boundary Fault. Across the dyke, alpha-, beta-, and gamma-Wenner, Schlumberger, half-Schlumberger and two-electrode configurations were employed. Azi-muthal two-electrode sounding was also studied over the fault. The interpretation of the results of apparent resistivity profiles across the Southern Boundary Fault suggests that the Wenner and two-electrode configurations possess certain diagnostic features which help in mapping a single lithological contact, provided sufficient resistivity contrast exists. Although Schlumberger configuration seems to be quite suitable, other configurations may also be usefully employed over the dyke.

Knock-on electrons produced by muons of different energies have been investigated in lead and copper with a cloud chamber by coincidence and anticoincidence technique. The probability of their production in lead is (5.82 ± 0.71)% per 1.27 cms Pb and in copper (7.64 ± 0.59)% per 1.27 cms Cu. Angles of emergent secondaries in Pb follow a cos2.5 θ distribution and in Cu a cos4 θ distribution.